I could talk at length about these skills, but he's already done so. He even has his own analysis of skills here.

Some pertinent quotes below.

The extensive rules for dealing with non-combat skills in other systems, both classic and modern, speaks of the desire of players to be able to know in some quantitative sense what their characters are good at. However, if we are to come up with any such system as a house rule for OD&D, it has to meet several basic parameters:

"Having" a given skill, NWP, or whathaveyou should not, as a rule, be a requirement for attempting any adventure-related action or for having a reasonable chance of success.

The system must be scalable, allowing for characters to improve existing skills by the expenditure of time and wealth or as a reward for a successfully-completed adventure (as described in my previous post),

And yet it must be simple enough that no OD&D product must be significantly altered to employ it (i.e., the referee should not have to go through every adventure and install DCs for every challenge or create a complete set of skills for every goblin) and that any referee can easily ad-hoc it during play.

. . .

Ramping Up the Dice
This is the system that I've implemented and described back in Skills: The Middle Road. It basically developed when I noted how often the d6 is used to resolve action in play (hardly a surprise given D&Ds pre-polyhedral Chainmail origins). For example, surprise is determined on a d6, with a roll of 5-6 indicating surprise. Getting lost is rolled on a d6. A roll of 1 or 2 on a d6 indicates successful foraging for food. And so on.

From there, it was a simple step to invert some of the rolls as given in a simple fashion: High is always good, low bad. And from there, it wasn't hard to imagine characters with relevant backgrounds and/or learned skills using something other than the ol' d6 to determine success. Instead of needing to roll a 1 or 2 on a d6 to find enough food, one had to roll a 5 or better--only it didn't have to be a d6; it could be on a d8, d10, or d12, depending on the skill of the character.

Unskilled
Skill Die: d6
No bonuses to die rolls

Skilled
Training: 1 month and 100o gp
Skill Die: d8
+1 bonus when making skill-related rolls with a 1d4, 1d6, or 1d8
+2 bonus when making skill-related rolls with a 1d10 or 1d12
+3 bonus when making skill-related rolls with a 1d20
+15% on making skill-related rolls with percentage dice

Expert
Training: 3 months and 300o gp
Skill Die: d10
+1 bonus when making skill-related rolls with a 1d4
+2 bonus when making skill-related rolls with a 1d6 or 1d8
+4 bonus when making skill-related rolls with a 1d10 or 1d12
+5 bonus when making skill-related rolls with a 1d20
+25% on making skill-related rolls with percentage dice

Master
Training: 6 months and 10,00o gp
Skill Die: d12
+2 bonus when making skill-related rolls with a 1d4
+3 bonus when making skill-related rolls with a 1d6 or 1d8
+5 bonus when making skill-related rolls with a 1d10 or 1d12
+8 bonus when making skill-related rolls with a 1d20
+40% on making skill-related rolls with percentage dice

I have little to say other then I am a big fan of this simple skill system, and that I am very sad that the blog The Rod of Lordly Might is no longer updated.

"the referee should assign an ad-hoc possibility for success. This can be a number that must be surpassed by the roll of the skill die (the goblin is generally facing the direction the character is approaching from, so the referee rules the thief must roll a 10 or better to sneak up on him), a percentile chance, or any other sort of roll.

In the latter two cases, the character's skill level grants a bonus to attempting the action"

I’m still thinking that the biggest trouble with skill systems in general, though, is when they lack partial success. Or the equivalent by spreading a final result over several rolls the way combat does. (Though in the latter case, you have to also keep the play between rolls interesting so it isn’t just roll-roll-roll.)

This system is amazingly elegant. It's is so simple! I'm currently considering implementing a straight d6 system in a game of my own. D6, because everyone has one. You can always raid the monopoly game and get some dice. Great for new players and people who may not have considered roleplaying games before. I also like the bell curve by using multiple dice. Therefore I'm going to use a 3d6 format. Could this system be modified for this? How would one spread or gain training or skill points in this system?